Small Engines (Lawn Mowers, etc.): Cant Start Poulan 220 LE, piston damage, compression stroke

Question
I have a Poulan 220 LE that will not start. I pulled off the cover and removed the brand new plug. I can see spark when I pull it through. I sprayed ether into the cylinder and tried to make it pop, nothing. It will not run on a shot through the carb either. The engine has good compression.

This one has me stumped. I have fuel, air and spark but can't get it to pop on ether or run after following the starting instructions. I used new gas/oil to try this as well.

Answer
Hello George:

Usually when you have Compression, Fuel and Spark, the Engine will Run. There are 2 Reasons for the Engine Not to Run; 1- Some Models Use a Flywheel Key and Others have the Flywheel Key Made as a Part of the Flywheel. If this Key is Damaged, the Plug Fires OUT OF TIME During the Power/Compression Stroke and the Engine will Not Run. The Following is a Basic Instruction File I made for Removing the Flywheel and Replacing the Flywheel/Flywheel Key.  Remove the Cover that Houses the Starter Assembly. Remove the Spark Plug and Use a Bolt the Same Diameter and Threads as the Spark Plug and About 3" Long. Thread the Bolt into the Spark Plug Hole Until it Engages the Piston. Slowly Tighten the Bolt Until you have Locked the Piston and it Does Not Move. **BE CAREFUL A LOT OF TORQUE IS NOT REQUIRED PISTON DAMAGE CAN OCCUR IF TO MUCH TORQUE IS USED ON THE STOP BOLT** Now **Remove the Flywheel Nut. Use a 3 Jaw Puller and Attach the Puller to the Flywheel. Look for a Puller with Flat Jaws. These Slide Under the Flywheel and Allow for Easier Removal. Tighten the Puller and then Hit the Puller with a Hammer. Tighten and Hit Again Until the Flywheel is Loose and Can be Removed from the Crankshaft. Note the Key that Aligns the Flywheel to the Crankshaft. This Key is Most Likely Sheared or Bent and Causing the Plug to Fire Slightly Out of Time and Causing a Compression Lock. There is Not Enough Compression to Kick Back But Enough to Cause the Engine to Seem to Have High Compression.**  2- The Exhaust Port, Muffler or Spark Arrestor Screen (inside the Muffler) are Restricted with Carbon and Requires Cleaning/Replacing. The Following is a Basic Instruction File for Doing a Diagnostic on the Engine for this Problem. Any Input is Appreciated. **Remove the Muffler and Make Sure the Exhaust Port is Clear. If it is, then Try to Start the engine with the Muffler Off. If it Starts and Runs Properly, then Clean the Spark Arrestor Screen in the Muffler or Replace the Muffler if Required. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

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Respectfully

John